<?php
function getUniqueCode($length = "")
{
	$code = md5(uniqid(rand(), true));
	if ($length != "")
	return substr($code, 0, $length);
	else
	return $code;
}
function distance($lat1, $lon1, $lat2, $lon2, $unit) {
	$theta 	= $lon1 - $lon2;
	$dist 	= sin(deg2rad($lat1)) * sin(deg2rad($lat2)) +  cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($theta));
	$dist 	= acos($dist);
	$dist 	= rad2deg($dist);
	$miles 	= $dist * 60 * 1.1515;
	$unit 	= strtoupper($unit);
	if ($unit == "K") {
		return ($miles * 1.609344);
	} else if ($unit == "N") {
		return ($miles * 0.8684);
	} else {
		return round($miles);
	}
}
?>